膜生物反应器处理垃圾渗滤液试验研究

利用膜生物反应器对垃圾渗滤液进行了试验研究,在不人为排泥的情况下,反应器连续运行60d。结果表明,系统运行稳定,短期内可以达到良好的处理效果(COD_(Cr)<300mg/L,NH_3—N<20mg/L,未检出SS和大肠杆菌)。并对其污泥特性进行了分析。     

Anaerobic treatment of Hong Kong leachate followed by chemical oxidation.

Landfill leachate of Hong Kong was first treated by the upflow anaerobic sludge blanket (UASB) process. At 37 degrees C, pH 7.1-8.5 and a HRT of 5.1-6.6 days, the process removed 66-90% of COD in the leachate for loading rates of 1-2.4 g-COD/l day depending on the strength of landfill leachate. The final effluent contained 1440-1910 mg-COD/l and 70-91 mg-BOD/l. About 92.5% of the total COD removed was converted to methane and the rest was converted to biomass with an average net growth yield of 0.053 g-VSS/g-COD-removed. The granules developed in the UASB reactor were 0.5-1.5 mm in size and exhibited good settleability. The UASB effluent was then further polished by two oxidation processes. The UASB-ozonation process removed 93.0% of the 12900 mg/l of COD from the raw leachate. The UASB-Fenton-ozonation process improved the COD removal efficiency to 99.3%. The final effluent had only 85 mg/l of COD and 10 mg/l of BOD5. Ozonation was most effectively conducted at pH 7-8 with the addition of 300 mg/l of H2O2 and for the duration of 30 min. Ozonation also significantly improved the biodegradability of the organic residues. Nearly 50% of these residues could be used as carbon source in denitrification.     

垃圾填埋场渗滤液处理技术及应用

渗滤液成分复杂,采用单一的处理方法不能满足其处理要求,需要通过不同方法进行优化组合与灵活应用.年轻填埋垃圾渗滤液具有良好的生化处理可行性,一般采用生物(包括好氧、厌氧或好氧与厌氧相结合)法,或以生物法为主结合前处理和物化深度处理的手段进行处理;而老龄填埋场渗滤液B/C逐渐降低可生化性差、氨氮浓度逐渐升高、难降解污染物质成分复杂且浓度高.针对老龄填埋场的渗滤液的水质特性,选择适宜的物化与生物相结合的手段对其处理,即提高B/C和降低氨氮浓度,又达到去除难降解有机物的目的.     

Treatment of landfill leachate by a pilot-scale modified Ludzack-Ettinger and sulfur-utilizing denitrification process.

Nitrogen removal efficiency of a pilot-scale system consisted of Modified Ludzack-Ettinger (MLE) followed by sulfur-utilizing denitrification (SUDNR) process was evaluated with a landfill leachate. For SUDNR, a down-flow mode sulfur packed bed reactor (SPBR) filled with sulfur and limestone particles was used. Although total nitrogen removal efficiency of the MLE process was about 80% at the recycle ratio of 4, effluent contained 350-450 mg/L NO(3-)-N. Up to a loading rate of 1.2 kg NO(3-)-N/m3-day, the SPBR could achieve complete removal of nitrate, and nitrate removal rate was kept to that level even at higher loading rate. When a COD/N ratio of MLE process was maintained at 2 instead of 4, more organics with molecular weight less than 500 were utilized for heterotrophic denitrification although denitrification was not complete with the lack of electron donors. Clogging in the SPBR, mainly by the accumulation of nitrogen gas in the pores, could easily be removed by introducing the effluent in an upward direction for 1 min at 1 hr intervals. The proposed treatment system could achieve nitrate free effluent with a slight increase in chemical cost. Furthermore, depending on further COD removal requirement after biological treatment, the proposed treatment system can be an economical solution.     

Post-treatment of biologically treated wastewater of agrochemical industry by sulfated chitosan composite nanofiltration membrane

The objective of this study is to treat the biologically treated wastewater using sulfated chitosan/ polyacrylonitrile (PAN) composite nanofiltration (NF) membrane to improve agrochemical industry wastewater quality for reuse. Although biological treatment is quite efficient, the wastewater does not meet the reuse criteria. Hence, further treatment to improve the water quality is investigated. Sulfated chitosan composite NF membranes, having a PAN ultrafiltration membrane as the substrate, are prepared by coating and cross-linking methods. The effects of membrane preparation conditions on the rejection and permeation performance of the membranes are studied. The new membranes are characterized by NMR and scanning electron micrograph. Wastewater from agrochemical industry contains high concentrations of organic matter, color, heavy metals and other toxic substances. The operating variables studied are applied pressure (3-15 atm) and feed flowrate (4-16 L/min). It is found that the observed rejection (R(o)) increases with increase in feed pressure at constant feed flowrate. The rejection of cations follows the sequence: R(o)(Zn2+) > R(o)(Ni2+) > R(o)(CU2+) > R(o)(Cd2+) for wastewater. It is observed that the order of solute rejection sequence is inversely proportional to the diffusion coefficients.     

三维电氧化-光芬顿-电催化氧化组合工艺处理垃圾渗滤液膜浓缩液中试研究

采用"三维电氧化+光芬顿+电催化氧化"组合的高级氧化工艺,以深圳某垃圾填埋厂垃圾渗滤液膜浓缩液为处理对象,进行了120 d的中试,考察组合工艺各处理单元对膜浓缩液中C O D、氨氮和总氮的去除效率,并评估了处理成本.试验结果表明上述组合工艺对膜浓缩液中COD的去除率达到98.3％,氨氮的去除率达到98.9％,总氮的去除...     

UASB-水解酸化-接触氧化工艺处理阿维菌素废水

采用UASB-水解酸化-接触氧化法处理阿维菌素废水,其中高浓度废水直接采用UASB处理,出水和综合废水混合经水解酸化后利用接触氧化法进行处理,系统处理效率高,运行稳定,CODCr去除率为97%,出水水质达到<污水综合排放标准>(GB 8978-1996)二级标准.     

生活垃圾填埋场渗滤液超临界水氧化试验研究

采用间歇式超临界水氧化反应装置,用过氧化氢为氧化剂,对生活垃圾填埋场渗滤液进行处理,考察了反应温度、压力、停留时间等因素对氧化效果的影响。结果表明:超临界水氧化对渗滤液COD和TOC的去除率随着反应温度、压力、停留时间的增加而显著提高。当渗滤液原水COD、TOC和BOD的质量浓度分别为8 119、2 289和971 mg/L时,在反应温度405℃,压力25 MPa,停留时间37.1 s的条件下,经超临界水氧化反应后,渗滤液中COD和TOC的去除率分别达到了98.8%和97.6%。此外,超临界水氧化反应能明显改善渗滤液的可生化性,反应后渗滤液的生化比由0.12提高到0.55。     

Treatment of taste and odor material by oxidation and adsorption.

Massive blooms of blue-green algae in reservoirs produce the musty-earthy taste and odor, which are caused by compounds such as 2-MIB and geosmin. 2-MIB and geosmin are rarely removed by conventional water treatment. Their presence in the drinking water, even at low levels (ng/L), can be detected and it creates consumer complaints. So those concentrations have to be controlled as low as possible in the drinking water. The removals by oxidation (O3, Cl2, ClO2) and adsorption (PAC, filter/adsorber) were studied at laboratory and pilot plant (50 m3/d) to select suitable 2-MIB and geosmin treatment processes. The following conclusions were derived from the study. Both of the threshold odor levels for 2-MIB and geosmin appeared to be 30 ng/L as a consequence of a lab test. For any given PAC dosage in a jar-test, removal efficiencies of 2-MIB and geosmin were increased in proportion to PAC dosage and were independent of their initial concentration in raw water for the tested PAC dosages. In comparison of geosmin with 2-MIB, the adsorption efficiency of geosmin by PAC was superior to that of 2-MIB. The required PAC dosages to control below the threshold odor level were 30 mg/L for geosmin and 50 mg/L for 2-MIB at 100 ng/L of initial concentration. Removal efficiencies of odor materials by Cl2, ClO2, and O3 were very weak under the limited dosage (1.5 mg/L), however increased ozone dosage (3.8 mg O3/L) showed high removal efficiency (84.8% for 2-MIB) at contact time 6.4 minutes. According to the initial concentrations of 2-MIB and geosmin, their removal efficiencies by filter/adsorber differed from 25.7% to 88.4%. For all those, however, remaining concentrations of target materials in finished waters were maintained below 30 ng/L. The longer run-time given for the filter/adsorber, the higher the effluent concentration generated. So it is necessary that the run-time of the filter/adsorber be decreased, when 2-MIB or geosmin occurs in raw water.     

混凝沉淀-UASB-水解酸化-接触氧化处理抗生素废水

通过对浙江某制药有限公司废水处理工程投标文件的评审和筛选,从处理工艺的合理性评价、中试结果剖析及主要经济指标等几个方面的综合比较,提出了中标推荐工艺。在此基础上,介绍了推荐工艺的试验研究及工艺参数的确定。运行结果表明,当进水CODCr为9650mg/L时,生化系统出水CODCr<300mg/L,电耗及运行费用仅分别为1.446kW.h/m3和1.838元/m3。     

铁碳微电解——ABR——接触氧化工艺处理糠醛废水

糠醛废水是一种高浓度难处理的有机废水,介绍了铁碳微电解—ABR—接触氧化工艺在实际工程中处理糠醛废水的启动与运行。结果表明,该工艺对CODCr、BOD5、SS等污染物的去除效果较好,同时指出工程在启动运行中存在的一些问题。     

高COD洗舱含油废水混凝破乳-芬顿氧化预处理工艺研究

船舶洗舱废水直接排放会污染环境,排放前必须经过各种处理工艺的净化,而含油废水处理是其中的重点和难点。实验选取重庆某公司洗船中心最不利工况下的高COD洗舱含油废水,通过混凝破乳和芬顿氧化进行处理,分析了混凝破乳过程中混凝剂种类、投加量、pH值和搅拌时间等影响因素,确定了芬顿氧化过程的适宜条件,包括H₂O₂浓度、Fe²⁺浓度、反应时间等,并通过正交实验确定了洗舱含油废水预处理的最优条件。结果表明：PAC为适宜的无机混凝剂,其混凝破乳适宜的投加量为75 mg/L、初始pH值为8、搅拌时间为3 min;芬顿氧化适宜的H₂O₂和Fe²⁺浓度分别为12 500和1 250 mg/L、反应时间为120 min。在最优条件下,实验水样的COD总去除率可达70%,TP和石油类几乎全部去除。本研究成果为长江沿岸某城市港口洗舱废水处理项目的预处理工艺提供了工程设计和调试运行的理论指导。     

Fe-O/CeO_2催化剂的制备、表征及其对垃圾渗滤液微波催化氧化活性的研究

以浸渍法制备用于常温常压微波催化氧化工艺的负载型Fe-O/CeO_2催化剂并通过XRD和SEM手段进行表征;利用优化制备后的催化剂进行微波催化氧化垃圾渗滤液的研究.结果表明:Fe-O/CeO_2催化剂中活性组分Fe以α-Fe_2O_3和CeFe_2的形式存在.在渗滤液初始COD_(Cr)5 736 mg/L、氨氮1 840 mg/L、色度500倍和pH 8.69的条件下,在Fe-O/CeO_2投加量10 g/L、H_2O_2(30%)投加量22.5 mL/L、微波功率800 W、微波辐射时间10 min和水样初始浓度C_(水样)/C_(原水)为100%的最佳运行条件下,微波催化氧化工艺对COD_(Cr)、氨氮和色度的去除率分别为73%、78%和85%;在反应的第4～8 min和第2～8 min,COD_(Cr)和氨氮去除率分别与反应时间呈近似直线的关系.     

Impact of Microcystis aeruginosa on membrane fouling in a biologically treated effluent

Microcystis aeruginosa was cultured in biologically treated municipal effluent to simulate blue-green algal bloom conditions in a treatment lagoon. The effect of algae in the early, mid and late phases of growth on membrane fouling, chemical coagulation (alum or aluminium chlorohydrate (ACH)) and hydraulic cleaning on the microfiltration of this effluent was investigated. The effect of M. aeruginosa in the early phase was negligible and gave a similar flux profile and permeate volume to that of effluent alone. The increase in M. aeruginosa concentration for the mid and late phases caused a significant reduction in permeate volume compared with the early phase. Full flux recovery was achieved with an alum dose of 1 mg Al3+ L(-1) (early phase) and 10 mg Al3+ L(-1) (mid phase), demonstrating that membrane fouling was hydraulically reversible. For the late phase, the highest flux recovery was 89%, which was achieved with an alum dose of 5 mg Al3+ L(-1). Higher alum dosages resulted in a reduction in flux recovery. The use of 1.5 pm pre-filtration after alum treatment showed little improvement in water quality but led to a drastic reduction in flux recovery, which was attributed to diminishing the protective layer on the membrane surface, thus enabling internal fouling. The performance of ACH was comparable to alum at low dissolved organic carbon (DOC) and cell concentration, but was not as effective as alum at high DOC and cell concentration due to the formation of more compact ACH flocs, which resulted in a higher cake layer specific resistance, leading to the deterioration of performance.     

Fenton试剂对垃圾渗滤液的后处理

采用由H_2O_2和FeSO_4配制成的Fenton试剂,对垃圾渗滤液进行了后处理;考察了渗滤液的pH值,H_2O_2和FeSO_4的投加量及反应时间对COD和色度的去除效果。试验确定最佳条件为:pH值3.0,FeSO_41500mg/L,H_2O_220mL/L,反应时间60min,此时COD与色度去除率分别为79.7%和95.2%。     

水解酸化-A/O-催化氧化-接触氧化处理高浓度制药废水

在对有关高浓度制药废水处理工程投标文件筛选及其中试结果剖析的基础上 ,提出了水解酸化 -A/O -催化氧化 -接触氧化为主体的优化工艺 ,并进行优化工艺中试试验。结果表明 ,当进水COD为 1 2 0 0 0mg/L左右时 ,可使出水COD达 30 0mg/L以下。同时 ,对其应用于工程实际的可行性进行了讨论。     

Ozone catalysed with solids as an advanced oxidation process for landfill leachate treatment.

Heterogeneous catalytic ozonation (HCO) of wastewater is gaining both research and industrial interests. It is proved to be an advanced oxidation process since it involves hydroxyl radicals as oxidation species. Few studies have been carried out to test HCO in the treatment of landfill leachates. This work has been carried out to test three types of catalysts: activated carbon (AC), expanded perlite (EP) and titanium dioxide (TiO2) combined with ozone at 80 g/m3 gas concentration for the treatment of a leachate generated by Jebel Chakir landfill site near Tunis-capital of Tunisia. The work has shown a reduction in COD of about 45% and an increase in biodegradability (BOD5/COD) from 0.1 to 0.34. A catalyst concentration of 0.7 g/L was found optimal for the treatment of the leachate.     

混凝气浮-ABR-接触氧化工艺处理洗毛废水

洗毛废水是一种SS含量高、难生化降解的高浓度有机废水,处理难度大.针对重庆某纺织公司的洗毛废水,设计采用混凝气浮-ABR-接触氧化工艺处理,出水水质达到<污水综合排放标准>(GB 8978-1996)一级标准.在运行调试的过程中,根据洗毛废水的特点,对处理工艺进行了少量的改进.实践证明,在进水污染物含量远高于设计值时,出水水质仍然能够稳定达标.     

混凝气浮-IC-接触氧化工艺处理纤维板废水

采用混凝气浮一IC一接触氧化法处理纤维板废水.工程运行结果表明:该工艺处理后出水水质稳定,CODCr142 mg/L,BOD545 mg/L,SS 96 mg/L,pH 6.5,色度37倍,达到<污水综合排放标准>(GB 8978-1996)湿法纤维板工业二级排放标准.     

Foulant characterization of the NF membranes with and without pretreatment of biologically treated wastewater.

In this study, different pretreatment methods such as ferric chloride (FeCl3) flocculation and powdered activated carbon (PAC) adsorption were evaluated in terms of their capability in removing effluent organic matter (EfOM) and the characteristics of the foulants on the NF membranes. A detailed experiment was conducted with two NF membranes (NTR 729HF with MWCO 700 daltons and LF 10 with MWCO 200 daltons). With pretreatment, the concentration of organic matter on the membranes decreased to 5.671 x 10(-3) (NTR 729HF) and 4.940 x 10(-3) (LF 10) mg EfOM/cm2 of membrane from 6.372 x 10(-3) (NTR 729HF) and 4.979 x 10(-3) (LF 10) mg EfOM/cm2 of membrane. The MW of the solute fraction of biologically treated sewage effluent (BTSE) ranged from 250 daltons to about 3573 (the most important being 250-520 daltons). The weight-averaged MW values of the foulants on the NTR 729HF membrane reduced from 304 daltons without pre-treatment to 208 daltons with pretreatment. In the case of EfOM, the small molecules (MW 300 to 500 daltons) are mainly responsible for the membrane fouling. Thus, the MW distribution of organic matter in the effluent and in the foulant can be used as a representative tool to evaluate the efficiency of pretreatment and NF and in the selection of their operating conditions.